A passenger on Ryanair flight FR1879 from Thessaloniki, Greece, to Memmingen, Germany, was injured after a window broke during the flight, causing a sudden cabin decompression that partially pulled the upper part of his body outside the aircraft.

The incident occurred on Friday shortly after departure from Thessaloniki. The aircraft subsequently returned to its point of origin and landed safely. Ryanair confirmed that one of the passenger windows became dislodged in flight but did not specify what caused the damage.

The flight was operated by a Boeing 737-800 registered 9H-QEU, an aircraft registered to Malta Air, Ryanair’s sister airline. The aircraft, bearing manufacturer serial number 36569, made its first flight on March 7, 2008. It is configured to carry 189 passengers and is powered by two CFM56-7B26 engines.

According to two airport sources cited by Reuters, part of the engine separated in flight and struck a passenger-cabin window. Videos posted on social media reportedly show extensive engine damage, including missing fan blades, which could point to an uncontained engine failure in which internal components penetrate the engine casing and are projected toward the aircraft fuselage.

The injured passenger, a Serbian national, was taken to AHEPA University General Hospital in Thessaloniki. According to the Serbian consulate, his injuries were not life-threatening, while doctors continued to assess their full extent.

Serbian media quoted a passenger as saying that the man’s head and shoulders were outside the aircraft before fellow passengers managed to pull him back into the cabin. Footage from inside the aircraft shows the broken window and deployed oxygen masks.

The U.S. Federal Aviation Administration confirmed that the aircraft was a Boeing 737 NG, the generation preceding the current 737 MAX family. Boeing said it was supporting Ryanair and the investigation being led by North Macedonia, over whose territory the incident reportedly occurred.

Ryanair said the aircraft landed normally and that passengers returned to the terminal. Flightradar24 data also showed that the aircraft operating flight FR1879 returned to Thessaloniki shortly after departure.

Available flight-tracking data indicate that the same aircraft had also returned to Thessaloniki the previous evening while operating a flight to Sarajevo, again shortly after takeoff. The reason for that earlier return remains unclear.

Ryanair and its affiliated airlines use CFM56 engines manufactured by CFM International, a joint venture between U.S.-based GE Aerospace and France’s Safran, on their Boeing 737 NG aircraft. CFM did not comment on the incident.

The aircraft remained grounded in Thessaloniki following the event as investigators worked to establish the cause of the failure and the exact sequence of events.

A similar accident occurred in 2018 on a Southwest Airlines Boeing 737 NG. In that case, a fan blade failure caused damage to the fuselage and shattered a window, partially pulling a passenger outside the aircraft. She later died from her injuries.

Following that accident, the U.S. National Transportation Safety Board called on Boeing to redesign the fan cowl structure on 737 NG aircraft. In 2023, the FAA issued a directive requiring the relevant design changes to be implemented by July 2028.